| /* -*- Mode: C; c-file-style: "python" -*- */ |
| |
| #include <Python.h> |
| #include <locale.h> |
| |
| /* Case-insensitive string match used for nan and inf detection; t should be |
| lower-case. Returns 1 for a successful match, 0 otherwise. */ |
| |
| static int |
| case_insensitive_match(const char *s, const char *t) |
| { |
| while(*t && Py_TOLOWER(*s) == *t) { |
| s++; |
| t++; |
| } |
| return *t ? 0 : 1; |
| } |
| |
| /* _Py_parse_inf_or_nan: Attempt to parse a string of the form "nan", "inf" or |
| "infinity", with an optional leading sign of "+" or "-". On success, |
| return the NaN or Infinity as a double and set *endptr to point just beyond |
| the successfully parsed portion of the string. On failure, return -1.0 and |
| set *endptr to point to the start of the string. */ |
| |
| double |
| _Py_parse_inf_or_nan(const char *p, char **endptr) |
| { |
| double retval; |
| const char *s; |
| int negate = 0; |
| |
| s = p; |
| if (*s == '-') { |
| negate = 1; |
| s++; |
| } |
| else if (*s == '+') { |
| s++; |
| } |
| if (case_insensitive_match(s, "inf")) { |
| s += 3; |
| if (case_insensitive_match(s, "inity")) |
| s += 5; |
| retval = negate ? -Py_HUGE_VAL : Py_HUGE_VAL; |
| } |
| #ifdef Py_NAN |
| else if (case_insensitive_match(s, "nan")) { |
| s += 3; |
| retval = negate ? -Py_NAN : Py_NAN; |
| } |
| #endif |
| else { |
| s = p; |
| retval = -1.0; |
| } |
| *endptr = (char *)s; |
| return retval; |
| } |
| |
| /** |
| * PyOS_ascii_strtod: |
| * @nptr: the string to convert to a numeric value. |
| * @endptr: if non-%NULL, it returns the character after |
| * the last character used in the conversion. |
| * |
| * Converts a string to a #gdouble value. |
| * This function behaves like the standard strtod() function |
| * does in the C locale. It does this without actually |
| * changing the current locale, since that would not be |
| * thread-safe. |
| * |
| * This function is typically used when reading configuration |
| * files or other non-user input that should be locale independent. |
| * To handle input from the user you should normally use the |
| * locale-sensitive system strtod() function. |
| * |
| * If the correct value would cause overflow, plus or minus %HUGE_VAL |
| * is returned (according to the sign of the value), and %ERANGE is |
| * stored in %errno. If the correct value would cause underflow, |
| * zero is returned and %ERANGE is stored in %errno. |
| * If memory allocation fails, %ENOMEM is stored in %errno. |
| * |
| * This function resets %errno before calling strtod() so that |
| * you can reliably detect overflow and underflow. |
| * |
| * Return value: the #gdouble value. |
| **/ |
| |
| #ifndef PY_NO_SHORT_FLOAT_REPR |
| |
| double |
| _PyOS_ascii_strtod(const char *nptr, char **endptr) |
| { |
| double result; |
| _Py_SET_53BIT_PRECISION_HEADER; |
| |
| assert(nptr != NULL); |
| /* Set errno to zero, so that we can distinguish zero results |
| and underflows */ |
| errno = 0; |
| |
| _Py_SET_53BIT_PRECISION_START; |
| result = _Py_dg_strtod(nptr, endptr); |
| _Py_SET_53BIT_PRECISION_END; |
| |
| if (*endptr == nptr) |
| /* string might represent an inf or nan */ |
| result = _Py_parse_inf_or_nan(nptr, endptr); |
| |
| return result; |
| |
| } |
| |
| #else |
| |
| /* |
| Use system strtod; since strtod is locale aware, we may |
| have to first fix the decimal separator. |
| |
| Note that unlike _Py_dg_strtod, the system strtod may not always give |
| correctly rounded results. |
| */ |
| |
| double |
| _PyOS_ascii_strtod(const char *nptr, char **endptr) |
| { |
| char *fail_pos; |
| double val = -1.0; |
| struct lconv *locale_data; |
| const char *decimal_point; |
| size_t decimal_point_len; |
| const char *p, *decimal_point_pos; |
| const char *end = NULL; /* Silence gcc */ |
| const char *digits_pos = NULL; |
| int negate = 0; |
| |
| assert(nptr != NULL); |
| |
| fail_pos = NULL; |
| |
| locale_data = localeconv(); |
| decimal_point = locale_data->decimal_point; |
| decimal_point_len = strlen(decimal_point); |
| |
| assert(decimal_point_len != 0); |
| |
| decimal_point_pos = NULL; |
| |
| /* Parse infinities and nans */ |
| val = _Py_parse_inf_or_nan(nptr, endptr); |
| if (*endptr != nptr) |
| return val; |
| |
| /* Set errno to zero, so that we can distinguish zero results |
| and underflows */ |
| errno = 0; |
| |
| /* We process the optional sign manually, then pass the remainder to |
| the system strtod. This ensures that the result of an underflow |
| has the correct sign. (bug #1725) */ |
| p = nptr; |
| /* Process leading sign, if present */ |
| if (*p == '-') { |
| negate = 1; |
| p++; |
| } |
| else if (*p == '+') { |
| p++; |
| } |
| |
| /* Some platform strtods accept hex floats; Python shouldn't (at the |
| moment), so we check explicitly for strings starting with '0x'. */ |
| if (*p == '0' && (*(p+1) == 'x' || *(p+1) == 'X')) |
| goto invalid_string; |
| |
| /* Check that what's left begins with a digit or decimal point */ |
| if (!Py_ISDIGIT(*p) && *p != '.') |
| goto invalid_string; |
| |
| digits_pos = p; |
| if (decimal_point[0] != '.' || |
| decimal_point[1] != 0) |
| { |
| /* Look for a '.' in the input; if present, it'll need to be |
| swapped for the current locale's decimal point before we |
| call strtod. On the other hand, if we find the current |
| locale's decimal point then the input is invalid. */ |
| while (Py_ISDIGIT(*p)) |
| p++; |
| |
| if (*p == '.') |
| { |
| decimal_point_pos = p++; |
| |
| /* locate end of number */ |
| while (Py_ISDIGIT(*p)) |
| p++; |
| |
| if (*p == 'e' || *p == 'E') |
| p++; |
| if (*p == '+' || *p == '-') |
| p++; |
| while (Py_ISDIGIT(*p)) |
| p++; |
| end = p; |
| } |
| else if (strncmp(p, decimal_point, decimal_point_len) == 0) |
| /* Python bug #1417699 */ |
| goto invalid_string; |
| /* For the other cases, we need not convert the decimal |
| point */ |
| } |
| |
| if (decimal_point_pos) { |
| char *copy, *c; |
| /* Create a copy of the input, with the '.' converted to the |
| locale-specific decimal point */ |
| copy = (char *)PyMem_MALLOC(end - digits_pos + |
| 1 + decimal_point_len); |
| if (copy == NULL) { |
| *endptr = (char *)nptr; |
| errno = ENOMEM; |
| return val; |
| } |
| |
| c = copy; |
| memcpy(c, digits_pos, decimal_point_pos - digits_pos); |
| c += decimal_point_pos - digits_pos; |
| memcpy(c, decimal_point, decimal_point_len); |
| c += decimal_point_len; |
| memcpy(c, decimal_point_pos + 1, |
| end - (decimal_point_pos + 1)); |
| c += end - (decimal_point_pos + 1); |
| *c = 0; |
| |
| val = strtod(copy, &fail_pos); |
| |
| if (fail_pos) |
| { |
| if (fail_pos > decimal_point_pos) |
| fail_pos = (char *)digits_pos + |
| (fail_pos - copy) - |
| (decimal_point_len - 1); |
| else |
| fail_pos = (char *)digits_pos + |
| (fail_pos - copy); |
| } |
| |
| PyMem_FREE(copy); |
| |
| } |
| else { |
| val = strtod(digits_pos, &fail_pos); |
| } |
| |
| if (fail_pos == digits_pos) |
| goto invalid_string; |
| |
| if (negate && fail_pos != nptr) |
| val = -val; |
| *endptr = fail_pos; |
| |
| return val; |
| |
| invalid_string: |
| *endptr = (char*)nptr; |
| errno = EINVAL; |
| return -1.0; |
| } |
| |
| #endif |
| |
| /* PyOS_ascii_strtod is DEPRECATED in Python 2.7 and 3.1 */ |
| |
| double |
| PyOS_ascii_strtod(const char *nptr, char **endptr) |
| { |
| char *fail_pos; |
| const char *p; |
| double x; |
| |
| if (PyErr_WarnEx(PyExc_DeprecationWarning, |
| "PyOS_ascii_strtod and PyOS_ascii_atof are " |
| "deprecated. Use PyOS_string_to_double " |
| "instead.", 1) < 0) |
| return -1.0; |
| |
| /* _PyOS_ascii_strtod already does everything that we want, |
| except that it doesn't parse leading whitespace */ |
| p = nptr; |
| while (Py_ISSPACE(*p)) |
| p++; |
| x = _PyOS_ascii_strtod(p, &fail_pos); |
| if (fail_pos == p) |
| fail_pos = (char *)nptr; |
| if (endptr) |
| *endptr = (char *)fail_pos; |
| return x; |
| } |
| |
| /* PyOS_ascii_strtod is DEPRECATED in Python 2.7 and 3.1 */ |
| |
| double |
| PyOS_ascii_atof(const char *nptr) |
| { |
| return PyOS_ascii_strtod(nptr, NULL); |
| } |
| |
| /* PyOS_string_to_double is the recommended replacement for the deprecated |
| PyOS_ascii_strtod and PyOS_ascii_atof functions. It converts a |
| null-terminated byte string s (interpreted as a string of ASCII characters) |
| to a float. The string should not have leading or trailing whitespace (in |
| contrast, PyOS_ascii_strtod allows leading whitespace but not trailing |
| whitespace). The conversion is independent of the current locale. |
| |
| If endptr is NULL, try to convert the whole string. Raise ValueError and |
| return -1.0 if the string is not a valid representation of a floating-point |
| number. |
| |
| If endptr is non-NULL, try to convert as much of the string as possible. |
| If no initial segment of the string is the valid representation of a |
| floating-point number then *endptr is set to point to the beginning of the |
| string, -1.0 is returned and again ValueError is raised. |
| |
| On overflow (e.g., when trying to convert '1e500' on an IEEE 754 machine), |
| if overflow_exception is NULL then +-Py_HUGE_VAL is returned, and no Python |
| exception is raised. Otherwise, overflow_exception should point to |
| a Python exception, this exception will be raised, -1.0 will be returned, |
| and *endptr will point just past the end of the converted value. |
| |
| If any other failure occurs (for example lack of memory), -1.0 is returned |
| and the appropriate Python exception will have been set. |
| */ |
| |
| double |
| PyOS_string_to_double(const char *s, |
| char **endptr, |
| PyObject *overflow_exception) |
| { |
| double x, result=-1.0; |
| char *fail_pos; |
| |
| errno = 0; |
| PyFPE_START_PROTECT("PyOS_string_to_double", return -1.0) |
| x = _PyOS_ascii_strtod(s, &fail_pos); |
| PyFPE_END_PROTECT(x) |
| |
| if (errno == ENOMEM) { |
| PyErr_NoMemory(); |
| fail_pos = (char *)s; |
| } |
| else if (!endptr && (fail_pos == s || *fail_pos != '\0')) |
| PyErr_Format(PyExc_ValueError, |
| "could not convert string to float: " |
| "%.200s", s); |
| else if (fail_pos == s) |
| PyErr_Format(PyExc_ValueError, |
| "could not convert string to float: " |
| "%.200s", s); |
| else if (errno == ERANGE && fabs(x) >= 1.0 && overflow_exception) |
| PyErr_Format(overflow_exception, |
| "value too large to convert to float: " |
| "%.200s", s); |
| else |
| result = x; |
| |
| if (endptr != NULL) |
| *endptr = fail_pos; |
| return result; |
| } |
| |
| /* Given a string that may have a decimal point in the current |
| locale, change it back to a dot. Since the string cannot get |
| longer, no need for a maximum buffer size parameter. */ |
| Py_LOCAL_INLINE(void) |
| change_decimal_from_locale_to_dot(char* buffer) |
| { |
| struct lconv *locale_data = localeconv(); |
| const char *decimal_point = locale_data->decimal_point; |
| |
| if (decimal_point[0] != '.' || decimal_point[1] != 0) { |
| size_t decimal_point_len = strlen(decimal_point); |
| |
| if (*buffer == '+' || *buffer == '-') |
| buffer++; |
| while (Py_ISDIGIT(*buffer)) |
| buffer++; |
| if (strncmp(buffer, decimal_point, decimal_point_len) == 0) { |
| *buffer = '.'; |
| buffer++; |
| if (decimal_point_len > 1) { |
| /* buffer needs to get smaller */ |
| size_t rest_len = strlen(buffer + |
| (decimal_point_len - 1)); |
| memmove(buffer, |
| buffer + (decimal_point_len - 1), |
| rest_len); |
| buffer[rest_len] = 0; |
| } |
| } |
| } |
| } |
| |
| |
| /* From the C99 standard, section 7.19.6: |
| The exponent always contains at least two digits, and only as many more digits |
| as necessary to represent the exponent. |
| */ |
| #define MIN_EXPONENT_DIGITS 2 |
| |
| /* Ensure that any exponent, if present, is at least MIN_EXPONENT_DIGITS |
| in length. */ |
| Py_LOCAL_INLINE(void) |
| ensure_minimum_exponent_length(char* buffer, size_t buf_size) |
| { |
| char *p = strpbrk(buffer, "eE"); |
| if (p && (*(p + 1) == '-' || *(p + 1) == '+')) { |
| char *start = p + 2; |
| int exponent_digit_cnt = 0; |
| int leading_zero_cnt = 0; |
| int in_leading_zeros = 1; |
| int significant_digit_cnt; |
| |
| /* Skip over the exponent and the sign. */ |
| p += 2; |
| |
| /* Find the end of the exponent, keeping track of leading |
| zeros. */ |
| while (*p && Py_ISDIGIT(*p)) { |
| if (in_leading_zeros && *p == '0') |
| ++leading_zero_cnt; |
| if (*p != '0') |
| in_leading_zeros = 0; |
| ++p; |
| ++exponent_digit_cnt; |
| } |
| |
| significant_digit_cnt = exponent_digit_cnt - leading_zero_cnt; |
| if (exponent_digit_cnt == MIN_EXPONENT_DIGITS) { |
| /* If there are 2 exactly digits, we're done, |
| regardless of what they contain */ |
| } |
| else if (exponent_digit_cnt > MIN_EXPONENT_DIGITS) { |
| int extra_zeros_cnt; |
| |
| /* There are more than 2 digits in the exponent. See |
| if we can delete some of the leading zeros */ |
| if (significant_digit_cnt < MIN_EXPONENT_DIGITS) |
| significant_digit_cnt = MIN_EXPONENT_DIGITS; |
| extra_zeros_cnt = exponent_digit_cnt - |
| significant_digit_cnt; |
| |
| /* Delete extra_zeros_cnt worth of characters from the |
| front of the exponent */ |
| assert(extra_zeros_cnt >= 0); |
| |
| /* Add one to significant_digit_cnt to copy the |
| trailing 0 byte, thus setting the length */ |
| memmove(start, |
| start + extra_zeros_cnt, |
| significant_digit_cnt + 1); |
| } |
| else { |
| /* If there are fewer than 2 digits, add zeros |
| until there are 2, if there's enough room */ |
| int zeros = MIN_EXPONENT_DIGITS - exponent_digit_cnt; |
| if (start + zeros + exponent_digit_cnt + 1 |
| < buffer + buf_size) { |
| memmove(start + zeros, start, |
| exponent_digit_cnt + 1); |
| memset(start, '0', zeros); |
| } |
| } |
| } |
| } |
| |
| /* Remove trailing zeros after the decimal point from a numeric string; also |
| remove the decimal point if all digits following it are zero. The numeric |
| string must end in '\0', and should not have any leading or trailing |
| whitespace. Assumes that the decimal point is '.'. */ |
| Py_LOCAL_INLINE(void) |
| remove_trailing_zeros(char *buffer) |
| { |
| char *old_fraction_end, *new_fraction_end, *end, *p; |
| |
| p = buffer; |
| if (*p == '-' || *p == '+') |
| /* Skip leading sign, if present */ |
| ++p; |
| while (Py_ISDIGIT(*p)) |
| ++p; |
| |
| /* if there's no decimal point there's nothing to do */ |
| if (*p++ != '.') |
| return; |
| |
| /* scan any digits after the point */ |
| while (Py_ISDIGIT(*p)) |
| ++p; |
| old_fraction_end = p; |
| |
| /* scan up to ending '\0' */ |
| while (*p != '\0') |
| p++; |
| /* +1 to make sure that we move the null byte as well */ |
| end = p+1; |
| |
| /* scan back from fraction_end, looking for removable zeros */ |
| p = old_fraction_end; |
| while (*(p-1) == '0') |
| --p; |
| /* and remove point if we've got that far */ |
| if (*(p-1) == '.') |
| --p; |
| new_fraction_end = p; |
| |
| memmove(new_fraction_end, old_fraction_end, end-old_fraction_end); |
| } |
| |
| /* Ensure that buffer has a decimal point in it. The decimal point will not |
| be in the current locale, it will always be '.'. Don't add a decimal point |
| if an exponent is present. Also, convert to exponential notation where |
| adding a '.0' would produce too many significant digits (see issue 5864). |
| |
| Returns a pointer to the fixed buffer, or NULL on failure. |
| */ |
| Py_LOCAL_INLINE(char *) |
| ensure_decimal_point(char* buffer, size_t buf_size, int precision) |
| { |
| int digit_count, insert_count = 0, convert_to_exp = 0; |
| char *chars_to_insert, *digits_start; |
| |
| /* search for the first non-digit character */ |
| char *p = buffer; |
| if (*p == '-' || *p == '+') |
| /* Skip leading sign, if present. I think this could only |
| ever be '-', but it can't hurt to check for both. */ |
| ++p; |
| digits_start = p; |
| while (*p && Py_ISDIGIT(*p)) |
| ++p; |
| digit_count = Py_SAFE_DOWNCAST(p - digits_start, Py_ssize_t, int); |
| |
| if (*p == '.') { |
| if (Py_ISDIGIT(*(p+1))) { |
| /* Nothing to do, we already have a decimal |
| point and a digit after it */ |
| } |
| else { |
| /* We have a decimal point, but no following |
| digit. Insert a zero after the decimal. */ |
| /* can't ever get here via PyOS_double_to_string */ |
| assert(precision == -1); |
| ++p; |
| chars_to_insert = "0"; |
| insert_count = 1; |
| } |
| } |
| else if (!(*p == 'e' || *p == 'E')) { |
| /* Don't add ".0" if we have an exponent. */ |
| if (digit_count == precision) { |
| /* issue 5864: don't add a trailing .0 in the case |
| where the '%g'-formatted result already has as many |
| significant digits as were requested. Switch to |
| exponential notation instead. */ |
| convert_to_exp = 1; |
| /* no exponent, no point, and we shouldn't land here |
| for infs and nans, so we must be at the end of the |
| string. */ |
| assert(*p == '\0'); |
| } |
| else { |
| assert(precision == -1 || digit_count < precision); |
| chars_to_insert = ".0"; |
| insert_count = 2; |
| } |
| } |
| if (insert_count) { |
| size_t buf_len = strlen(buffer); |
| if (buf_len + insert_count + 1 >= buf_size) { |
| /* If there is not enough room in the buffer |
| for the additional text, just skip it. It's |
| not worth generating an error over. */ |
| } |
| else { |
| memmove(p + insert_count, p, |
| buffer + strlen(buffer) - p + 1); |
| memcpy(p, chars_to_insert, insert_count); |
| } |
| } |
| if (convert_to_exp) { |
| int written; |
| size_t buf_avail; |
| p = digits_start; |
| /* insert decimal point */ |
| assert(digit_count >= 1); |
| memmove(p+2, p+1, digit_count); /* safe, but overwrites nul */ |
| p[1] = '.'; |
| p += digit_count+1; |
| assert(p <= buf_size+buffer); |
| buf_avail = buf_size+buffer-p; |
| if (buf_avail == 0) |
| return NULL; |
| /* Add exponent. It's okay to use lower case 'e': we only |
| arrive here as a result of using the empty format code or |
| repr/str builtins and those never want an upper case 'E' */ |
| written = PyOS_snprintf(p, buf_avail, "e%+.02d", digit_count-1); |
| if (!(0 <= written && |
| written < Py_SAFE_DOWNCAST(buf_avail, size_t, int))) |
| /* output truncated, or something else bad happened */ |
| return NULL; |
| remove_trailing_zeros(buffer); |
| } |
| return buffer; |
| } |
| |
| /* see FORMATBUFLEN in unicodeobject.c */ |
| #define FLOAT_FORMATBUFLEN 120 |
| |
| /** |
| * PyOS_ascii_formatd: |
| * @buffer: A buffer to place the resulting string in |
| * @buf_size: The length of the buffer. |
| * @format: The printf()-style format to use for the |
| * code to use for converting. |
| * @d: The #gdouble to convert |
| * |
| * Converts a #gdouble to a string, using the '.' as |
| * decimal point. To format the number you pass in |
| * a printf()-style format string. Allowed conversion |
| * specifiers are 'e', 'E', 'f', 'F', 'g', 'G', and 'Z'. |
| * |
| * 'Z' is the same as 'g', except it always has a decimal and |
| * at least one digit after the decimal. |
| * |
| * Return value: The pointer to the buffer with the converted string. |
| * On failure returns NULL but does not set any Python exception. |
| **/ |
| char * |
| _PyOS_ascii_formatd(char *buffer, |
| size_t buf_size, |
| const char *format, |
| double d, |
| int precision) |
| { |
| char format_char; |
| size_t format_len = strlen(format); |
| |
| /* Issue 2264: code 'Z' requires copying the format. 'Z' is 'g', but |
| also with at least one character past the decimal. */ |
| char tmp_format[FLOAT_FORMATBUFLEN]; |
| |
| /* The last character in the format string must be the format char */ |
| format_char = format[format_len - 1]; |
| |
| if (format[0] != '%') |
| return NULL; |
| |
| /* I'm not sure why this test is here. It's ensuring that the format |
| string after the first character doesn't have a single quote, a |
| lowercase l, or a percent. This is the reverse of the commented-out |
| test about 10 lines ago. */ |
| if (strpbrk(format + 1, "'l%")) |
| return NULL; |
| |
| /* Also curious about this function is that it accepts format strings |
| like "%xg", which are invalid for floats. In general, the |
| interface to this function is not very good, but changing it is |
| difficult because it's a public API. */ |
| |
| if (!(format_char == 'e' || format_char == 'E' || |
| format_char == 'f' || format_char == 'F' || |
| format_char == 'g' || format_char == 'G' || |
| format_char == 'Z')) |
| return NULL; |
| |
| /* Map 'Z' format_char to 'g', by copying the format string and |
| replacing the final char with a 'g' */ |
| if (format_char == 'Z') { |
| if (format_len + 1 >= sizeof(tmp_format)) { |
| /* The format won't fit in our copy. Error out. In |
| practice, this will never happen and will be |
| detected by returning NULL */ |
| return NULL; |
| } |
| strcpy(tmp_format, format); |
| tmp_format[format_len - 1] = 'g'; |
| format = tmp_format; |
| } |
| |
| |
| /* Have PyOS_snprintf do the hard work */ |
| PyOS_snprintf(buffer, buf_size, format, d); |
| |
| /* Do various fixups on the return string */ |
| |
| /* Get the current locale, and find the decimal point string. |
| Convert that string back to a dot. */ |
| change_decimal_from_locale_to_dot(buffer); |
| |
| /* If an exponent exists, ensure that the exponent is at least |
| MIN_EXPONENT_DIGITS digits, providing the buffer is large enough |
| for the extra zeros. Also, if there are more than |
| MIN_EXPONENT_DIGITS, remove as many zeros as possible until we get |
| back to MIN_EXPONENT_DIGITS */ |
| ensure_minimum_exponent_length(buffer, buf_size); |
| |
| /* If format_char is 'Z', make sure we have at least one character |
| after the decimal point (and make sure we have a decimal point); |
| also switch to exponential notation in some edge cases where the |
| extra character would produce more significant digits that we |
| really want. */ |
| if (format_char == 'Z') |
| buffer = ensure_decimal_point(buffer, buf_size, precision); |
| |
| return buffer; |
| } |
| |
| char * |
| PyOS_ascii_formatd(char *buffer, |
| size_t buf_size, |
| const char *format, |
| double d) |
| { |
| if (PyErr_WarnEx(PyExc_DeprecationWarning, |
| "PyOS_ascii_formatd is deprecated, " |
| "use PyOS_double_to_string instead", 1) < 0) |
| return NULL; |
| |
| return _PyOS_ascii_formatd(buffer, buf_size, format, d, -1); |
| } |
| |
| #ifdef PY_NO_SHORT_FLOAT_REPR |
| |
| /* The fallback code to use if _Py_dg_dtoa is not available. */ |
| |
| PyAPI_FUNC(char *) PyOS_double_to_string(double val, |
| char format_code, |
| int precision, |
| int flags, |
| int *type) |
| { |
| char format[32]; |
| Py_ssize_t bufsize; |
| char *buf; |
| int t, exp; |
| int upper = 0; |
| |
| /* Validate format_code, and map upper and lower case */ |
| switch (format_code) { |
| case 'e': /* exponent */ |
| case 'f': /* fixed */ |
| case 'g': /* general */ |
| break; |
| case 'E': |
| upper = 1; |
| format_code = 'e'; |
| break; |
| case 'F': |
| upper = 1; |
| format_code = 'f'; |
| break; |
| case 'G': |
| upper = 1; |
| format_code = 'g'; |
| break; |
| case 'r': /* repr format */ |
| /* Supplied precision is unused, must be 0. */ |
| if (precision != 0) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| /* The repr() precision (17 significant decimal digits) is the |
| minimal number that is guaranteed to have enough precision |
| so that if the number is read back in the exact same binary |
| value is recreated. This is true for IEEE floating point |
| by design, and also happens to work for all other modern |
| hardware. */ |
| precision = 17; |
| format_code = 'g'; |
| break; |
| default: |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| |
| /* Here's a quick-and-dirty calculation to figure out how big a buffer |
| we need. In general, for a finite float we need: |
| |
| 1 byte for each digit of the decimal significand, and |
| |
| 1 for a possible sign |
| 1 for a possible decimal point |
| 2 for a possible [eE][+-] |
| 1 for each digit of the exponent; if we allow 19 digits |
| total then we're safe up to exponents of 2**63. |
| 1 for the trailing nul byte |
| |
| This gives a total of 24 + the number of digits in the significand, |
| and the number of digits in the significand is: |
| |
| for 'g' format: at most precision, except possibly |
| when precision == 0, when it's 1. |
| for 'e' format: precision+1 |
| for 'f' format: precision digits after the point, at least 1 |
| before. To figure out how many digits appear before the point |
| we have to examine the size of the number. If fabs(val) < 1.0 |
| then there will be only one digit before the point. If |
| fabs(val) >= 1.0, then there are at most |
| |
| 1+floor(log10(ceiling(fabs(val)))) |
| |
| digits before the point (where the 'ceiling' allows for the |
| possibility that the rounding rounds the integer part of val |
| up). A safe upper bound for the above quantity is |
| 1+floor(exp/3), where exp is the unique integer such that 0.5 |
| <= fabs(val)/2**exp < 1.0. This exp can be obtained from |
| frexp. |
| |
| So we allow room for precision+1 digits for all formats, plus an |
| extra floor(exp/3) digits for 'f' format. |
| |
| */ |
| |
| if (Py_IS_NAN(val) || Py_IS_INFINITY(val)) |
| /* 3 for 'inf'/'nan', 1 for sign, 1 for '\0' */ |
| bufsize = 5; |
| else { |
| bufsize = 25 + precision; |
| if (format_code == 'f' && fabs(val) >= 1.0) { |
| frexp(val, &exp); |
| bufsize += exp/3; |
| } |
| } |
| |
| buf = PyMem_Malloc(bufsize); |
| if (buf == NULL) { |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| |
| /* Handle nan and inf. */ |
| if (Py_IS_NAN(val)) { |
| strcpy(buf, "nan"); |
| t = Py_DTST_NAN; |
| } else if (Py_IS_INFINITY(val)) { |
| if (copysign(1., val) == 1.) |
| strcpy(buf, "inf"); |
| else |
| strcpy(buf, "-inf"); |
| t = Py_DTST_INFINITE; |
| } else { |
| t = Py_DTST_FINITE; |
| if (flags & Py_DTSF_ADD_DOT_0) |
| format_code = 'Z'; |
| |
| PyOS_snprintf(format, sizeof(format), "%%%s.%i%c", |
| (flags & Py_DTSF_ALT ? "#" : ""), precision, |
| format_code); |
| _PyOS_ascii_formatd(buf, bufsize, format, val, precision); |
| } |
| |
| /* Add sign when requested. It's convenient (esp. when formatting |
| complex numbers) to include a sign even for inf and nan. */ |
| if (flags & Py_DTSF_SIGN && buf[0] != '-') { |
| size_t len = strlen(buf); |
| /* the bufsize calculations above should ensure that we've got |
| space to add a sign */ |
| assert((size_t)bufsize >= len+2); |
| memmove(buf+1, buf, len+1); |
| buf[0] = '+'; |
| } |
| if (upper) { |
| /* Convert to upper case. */ |
| char *p1; |
| for (p1 = buf; *p1; p1++) |
| *p1 = Py_TOUPPER(*p1); |
| } |
| |
| if (type) |
| *type = t; |
| return buf; |
| } |
| |
| #else |
| |
| /* _Py_dg_dtoa is available. */ |
| |
| /* I'm using a lookup table here so that I don't have to invent a non-locale |
| specific way to convert to uppercase */ |
| #define OFS_INF 0 |
| #define OFS_NAN 1 |
| #define OFS_E 2 |
| |
| /* The lengths of these are known to the code below, so don't change them */ |
| static char *lc_float_strings[] = { |
| "inf", |
| "nan", |
| "e", |
| }; |
| static char *uc_float_strings[] = { |
| "INF", |
| "NAN", |
| "E", |
| }; |
| |
| |
| /* Convert a double d to a string, and return a PyMem_Malloc'd block of |
| memory contain the resulting string. |
| |
| Arguments: |
| d is the double to be converted |
| format_code is one of 'e', 'f', 'g', 'r'. 'e', 'f' and 'g' |
| correspond to '%e', '%f' and '%g'; 'r' corresponds to repr. |
| mode is one of '0', '2' or '3', and is completely determined by |
| format_code: 'e' and 'g' use mode 2; 'f' mode 3, 'r' mode 0. |
| precision is the desired precision |
| always_add_sign is nonzero if a '+' sign should be included for positive |
| numbers |
| add_dot_0_if_integer is nonzero if integers in non-exponential form |
| should have ".0" added. Only applies to format codes 'r' and 'g'. |
| use_alt_formatting is nonzero if alternative formatting should be |
| used. Only applies to format codes 'e', 'f' and 'g'. For code 'g', |
| at most one of use_alt_formatting and add_dot_0_if_integer should |
| be nonzero. |
| type, if non-NULL, will be set to one of these constants to identify |
| the type of the 'd' argument: |
| Py_DTST_FINITE |
| Py_DTST_INFINITE |
| Py_DTST_NAN |
| |
| Returns a PyMem_Malloc'd block of memory containing the resulting string, |
| or NULL on error. If NULL is returned, the Python error has been set. |
| */ |
| |
| static char * |
| format_float_short(double d, char format_code, |
| int mode, Py_ssize_t precision, |
| int always_add_sign, int add_dot_0_if_integer, |
| int use_alt_formatting, char **float_strings, int *type) |
| { |
| char *buf = NULL; |
| char *p = NULL; |
| Py_ssize_t bufsize = 0; |
| char *digits, *digits_end; |
| int decpt_as_int, sign, exp_len, exp = 0, use_exp = 0; |
| Py_ssize_t decpt, digits_len, vdigits_start, vdigits_end; |
| _Py_SET_53BIT_PRECISION_HEADER; |
| |
| /* _Py_dg_dtoa returns a digit string (no decimal point or exponent). |
| Must be matched by a call to _Py_dg_freedtoa. */ |
| _Py_SET_53BIT_PRECISION_START; |
| digits = _Py_dg_dtoa(d, mode, precision, &decpt_as_int, &sign, |
| &digits_end); |
| _Py_SET_53BIT_PRECISION_END; |
| |
| decpt = (Py_ssize_t)decpt_as_int; |
| if (digits == NULL) { |
| /* The only failure mode is no memory. */ |
| PyErr_NoMemory(); |
| goto exit; |
| } |
| assert(digits_end != NULL && digits_end >= digits); |
| digits_len = digits_end - digits; |
| |
| if (digits_len && !Py_ISDIGIT(digits[0])) { |
| /* Infinities and nans here; adapt Gay's output, |
| so convert Infinity to inf and NaN to nan, and |
| ignore sign of nan. Then return. */ |
| |
| /* ignore the actual sign of a nan */ |
| if (digits[0] == 'n' || digits[0] == 'N') |
| sign = 0; |
| |
| /* We only need 5 bytes to hold the result "+inf\0" . */ |
| bufsize = 5; /* Used later in an assert. */ |
| buf = (char *)PyMem_Malloc(bufsize); |
| if (buf == NULL) { |
| PyErr_NoMemory(); |
| goto exit; |
| } |
| p = buf; |
| |
| if (sign == 1) { |
| *p++ = '-'; |
| } |
| else if (always_add_sign) { |
| *p++ = '+'; |
| } |
| if (digits[0] == 'i' || digits[0] == 'I') { |
| strncpy(p, float_strings[OFS_INF], 3); |
| p += 3; |
| |
| if (type) |
| *type = Py_DTST_INFINITE; |
| } |
| else if (digits[0] == 'n' || digits[0] == 'N') { |
| strncpy(p, float_strings[OFS_NAN], 3); |
| p += 3; |
| |
| if (type) |
| *type = Py_DTST_NAN; |
| } |
| else { |
| /* shouldn't get here: Gay's code should always return |
| something starting with a digit, an 'I', or 'N' */ |
| strncpy(p, "ERR", 3); |
| p += 3; |
| assert(0); |
| } |
| goto exit; |
| } |
| |
| /* The result must be finite (not inf or nan). */ |
| if (type) |
| *type = Py_DTST_FINITE; |
| |
| |
| /* We got digits back, format them. We may need to pad 'digits' |
| either on the left or right (or both) with extra zeros, so in |
| general the resulting string has the form |
| |
| [<sign>]<zeros><digits><zeros>[<exponent>] |
| |
| where either of the <zeros> pieces could be empty, and there's a |
| decimal point that could appear either in <digits> or in the |
| leading or trailing <zeros>. |
| |
| Imagine an infinite 'virtual' string vdigits, consisting of the |
| string 'digits' (starting at index 0) padded on both the left and |
| right with infinite strings of zeros. We want to output a slice |
| |
| vdigits[vdigits_start : vdigits_end] |
| |
| of this virtual string. Thus if vdigits_start < 0 then we'll end |
| up producing some leading zeros; if vdigits_end > digits_len there |
| will be trailing zeros in the output. The next section of code |
| determines whether to use an exponent or not, figures out the |
| position 'decpt' of the decimal point, and computes 'vdigits_start' |
| and 'vdigits_end'. */ |
| vdigits_end = digits_len; |
| switch (format_code) { |
| case 'e': |
| use_exp = 1; |
| vdigits_end = precision; |
| break; |
| case 'f': |
| vdigits_end = decpt + precision; |
| break; |
| case 'g': |
| if (decpt <= -4 || decpt > |
| (add_dot_0_if_integer ? precision-1 : precision)) |
| use_exp = 1; |
| if (use_alt_formatting) |
| vdigits_end = precision; |
| break; |
| case 'r': |
| /* convert to exponential format at 1e16. We used to convert |
| at 1e17, but that gives odd-looking results for some values |
| when a 16-digit 'shortest' repr is padded with bogus zeros. |
| For example, repr(2e16+8) would give 20000000000000010.0; |
| the true value is 20000000000000008.0. */ |
| if (decpt <= -4 || decpt > 16) |
| use_exp = 1; |
| break; |
| default: |
| PyErr_BadInternalCall(); |
| goto exit; |
| } |
| |
| /* if using an exponent, reset decimal point position to 1 and adjust |
| exponent accordingly.*/ |
| if (use_exp) { |
| exp = decpt - 1; |
| decpt = 1; |
| } |
| /* ensure vdigits_start < decpt <= vdigits_end, or vdigits_start < |
| decpt < vdigits_end if add_dot_0_if_integer and no exponent */ |
| vdigits_start = decpt <= 0 ? decpt-1 : 0; |
| if (!use_exp && add_dot_0_if_integer) |
| vdigits_end = vdigits_end > decpt ? vdigits_end : decpt + 1; |
| else |
| vdigits_end = vdigits_end > decpt ? vdigits_end : decpt; |
| |
| /* double check inequalities */ |
| assert(vdigits_start <= 0 && |
| 0 <= digits_len && |
| digits_len <= vdigits_end); |
| /* decimal point should be in (vdigits_start, vdigits_end] */ |
| assert(vdigits_start < decpt && decpt <= vdigits_end); |
| |
| /* Compute an upper bound how much memory we need. This might be a few |
| chars too long, but no big deal. */ |
| bufsize = |
| /* sign, decimal point and trailing 0 byte */ |
| 3 + |
| |
| /* total digit count (including zero padding on both sides) */ |
| (vdigits_end - vdigits_start) + |
| |
| /* exponent "e+100", max 3 numerical digits */ |
| (use_exp ? 5 : 0); |
| |
| /* Now allocate the memory and initialize p to point to the start of |
| it. */ |
| buf = (char *)PyMem_Malloc(bufsize); |
| if (buf == NULL) { |
| PyErr_NoMemory(); |
| goto exit; |
| } |
| p = buf; |
| |
| /* Add a negative sign if negative, and a plus sign if non-negative |
| and always_add_sign is true. */ |
| if (sign == 1) |
| *p++ = '-'; |
| else if (always_add_sign) |
| *p++ = '+'; |
| |
| /* note that exactly one of the three 'if' conditions is true, |
| so we include exactly one decimal point */ |
| /* Zero padding on left of digit string */ |
| if (decpt <= 0) { |
| memset(p, '0', decpt-vdigits_start); |
| p += decpt - vdigits_start; |
| *p++ = '.'; |
| memset(p, '0', 0-decpt); |
| p += 0-decpt; |
| } |
| else { |
| memset(p, '0', 0-vdigits_start); |
| p += 0 - vdigits_start; |
| } |
| |
| /* Digits, with included decimal point */ |
| if (0 < decpt && decpt <= digits_len) { |
| strncpy(p, digits, decpt-0); |
| p += decpt-0; |
| *p++ = '.'; |
| strncpy(p, digits+decpt, digits_len-decpt); |
| p += digits_len-decpt; |
| } |
| else { |
| strncpy(p, digits, digits_len); |
| p += digits_len; |
| } |
| |
| /* And zeros on the right */ |
| if (digits_len < decpt) { |
| memset(p, '0', decpt-digits_len); |
| p += decpt-digits_len; |
| *p++ = '.'; |
| memset(p, '0', vdigits_end-decpt); |
| p += vdigits_end-decpt; |
| } |
| else { |
| memset(p, '0', vdigits_end-digits_len); |
| p += vdigits_end-digits_len; |
| } |
| |
| /* Delete a trailing decimal pt unless using alternative formatting. */ |
| if (p[-1] == '.' && !use_alt_formatting) |
| p--; |
| |
| /* Now that we've done zero padding, add an exponent if needed. */ |
| if (use_exp) { |
| *p++ = float_strings[OFS_E][0]; |
| exp_len = sprintf(p, "%+.02d", exp); |
| p += exp_len; |
| } |
| exit: |
| if (buf) { |
| *p = '\0'; |
| /* It's too late if this fails, as we've already stepped on |
| memory that isn't ours. But it's an okay debugging test. */ |
| assert(p-buf < bufsize); |
| } |
| if (digits) |
| _Py_dg_freedtoa(digits); |
| |
| return buf; |
| } |
| |
| |
| PyAPI_FUNC(char *) PyOS_double_to_string(double val, |
| char format_code, |
| int precision, |
| int flags, |
| int *type) |
| { |
| char **float_strings = lc_float_strings; |
| int mode; |
| |
| /* Validate format_code, and map upper and lower case. Compute the |
| mode and make any adjustments as needed. */ |
| switch (format_code) { |
| /* exponent */ |
| case 'E': |
| float_strings = uc_float_strings; |
| format_code = 'e'; |
| /* Fall through. */ |
| case 'e': |
| mode = 2; |
| precision++; |
| break; |
| |
| /* fixed */ |
| case 'F': |
| float_strings = uc_float_strings; |
| format_code = 'f'; |
| /* Fall through. */ |
| case 'f': |
| mode = 3; |
| break; |
| |
| /* general */ |
| case 'G': |
| float_strings = uc_float_strings; |
| format_code = 'g'; |
| /* Fall through. */ |
| case 'g': |
| mode = 2; |
| /* precision 0 makes no sense for 'g' format; interpret as 1 */ |
| if (precision == 0) |
| precision = 1; |
| break; |
| |
| /* repr format */ |
| case 'r': |
| mode = 0; |
| /* Supplied precision is unused, must be 0. */ |
| if (precision != 0) { |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| break; |
| |
| default: |
| PyErr_BadInternalCall(); |
| return NULL; |
| } |
| |
| return format_float_short(val, format_code, mode, precision, |
| flags & Py_DTSF_SIGN, |
| flags & Py_DTSF_ADD_DOT_0, |
| flags & Py_DTSF_ALT, |
| float_strings, type); |
| } |
| #endif /* ifdef PY_NO_SHORT_FLOAT_REPR */ |
